Not applicable.
1. Field of the Invention
The present invention is related to distributing power to rack mounted electronic devices. More particularly, the present invention is related to routing direct current power to a plurality of rack-mounted computer systems in server operation. More particularly still, the present invention is directed to placement and mounting of power bus bars, circuit breakers, and the like, for rack mounted server systems.
2. Background of the Invention
As the size of computers becomes smaller, so too does the number of computers that may be placed in one particular place. For persons and entities providing server services, e.g., Internet service providers (ISPs) and corporate computer departments, smaller computer footprints allow a smaller required area, or more computers in the same areas already allocated.
Given that each server is effectively just an individual computer, each of these devices must have at least a power cable and a cable to carry information to and from the server. In years past, when a single computer may have occupied an entire drawer in a rack-mounted system, having the necessary space for power and information cables was not of particular concern. However, with the increasingly smaller footprints of modem computers, the necessary space to provide adequate cabling to each of these servers becomes a major concern. The trend in the industry is to replace the cable-bundle approach to providing cable access with the use of a backplane board.
A backplane board is simply an electrical circuit board placed at substantially right angles to the insertion direction of rack-mounted server systems. In such a system, the act of pushing the computer into the rack physically couples the computer to the backplane board. In this way, digital signals and power may be coupled to the computer system. Further, use of the backplane board allows the rack-mounted computer system designer to move cable connections, if any, to more desirable locations.
While these backplane boards typically have little, if any, logic circuitry, the boards can fail. The failure modes could include failure of any onboard circuitry, as well as failure of electrical traces on the board itself caused by mechanical stresses involved in inserting and removing the computer systems. Regardless of the cause, replacing backplane boards is a major undertaking, which may include disassembly of a substantial portion, or all, of the rack-mounted system including removal of the various power distribution buses, thus disabling the entire rack-mounted system.
Thus, what is needed in the art is a mechanism to distribute power in a rack-mounted server system that provides necessary amperage-carrying capability for more power-intensive operations, that is easily repairable, and that need not be removed or of disassembled in the event that a backplane board of the server system needs to be replaced.
The problems noted above are solved in large part by a main power distribution assembly for rack mounted server systems, and the like, that places the power supply and return bars in hinged non-conductive containers that extend at least the partial height of the server system. Preferably, two of these power distribution assemblies are provided on each server system for providing fully redundant power supplies.
In normal operation, each of the power distribution assemblies is preferably placed, by swinging it about its center of rotation, in a closed position where each of the power distribution assemblies is very close to the chassis of the rack system. When service, maintenance, or repair needs to be done to the server system, each of the power distribution assemblies is preferably rotated about its hinge away from the closed position to an open position. In the open position, each of the power distribution assemblies preferably swings at least 90 degrees away from its closed position. Thus, when both power distribution assemblies are in their open position, operators and technicians have full access to any electrical components or cables that may traverse various locations at the back of the rack, including access to each chassis within the rack.
Preferably, however, each of the power distribution assemblies is capable of providing power to its respective chassis in the rack whether it is in the open or closed position. This capability has two aspects: power supplied to the power distribution assembly, and power from the power distribution assembly to the various chassis. Preferably, power is supplied to power rails within the power distribution assembly by way of a set of power cables supplying appropriate direct current (DC) voltage. These voltages are preferably provided from an array of onboard DC power supplies, preferably mounted near the bottom of the rack. However, this DC voltage may also be supplied by a customer from other power systems, e.g., a battery network. By coupling the power supply to the power distribution assembly with flexible cables, current may continue to flow whether the power distribution assemblies are in their closed or open positions. Likewise, power is provided from the power distribution assembly to the various chassis by way of flexible cables that couple between circuit breakers and the power distribution assembly and power backplane boards of each particular chassis.